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This section includes 10 Mcqs, each offering curated multiple-choice questions to sharpen your Computational Fluid Dynamics knowledge and support exam preparation. Choose a topic below to get started.
1. |
The Spalart-Allmaras model is best suited for ___________ |
A. | turbulent jet flows |
B. | turbulent mixing layers |
C. | turbulent boundary layers with slight pressure gradients |
D. | turbulent boundary layers with adverse pressure gradients |
Answer» E. | |
2. |
The rate of dissipation of kinematic eddy viscosity parameter is Cw1 (( frac{ tilde{ }}{ y})^2 f_w ). What is the length scale used here? |
A. | y |
B. | ( y)<sup>2</sup> |
C. | ( frac{C_{w1}}{y} ) |
D. | ( frac{y}{C_{w1}} ) |
Answer» B. ( y)<sup>2</sup> | |
3. |
The rate of production of the kinematic eddy viscosity parameter is related to ___________ |
A. | rate of dissipation of kinetic energy |
B. | turbulence frequency |
C. | vorticity |
D. | kinetic energy |
Answer» D. kinetic energy | |
4. |
Expand the Reynolds stress term (- rho overline{u_{i}^{ } u_{j}^{ }} ) for the Spalart-Allmaras model. |
A. | (- rho overline{u_{i}^{ } u_{j}^{ }} = rho overline{v} f_{v1} ( frac{ partial U_i}{ partial x_i}+ frac{ partial U_j}{ partial x_j}) ) |
B. | (- rho overline{u_{i}^{ } u_{j}^{ }} = rho overline{v} f_{v1} ( frac{ partial U_i}{ partial x_j}+ frac{ partial U_j}{ partial x_i}) ) |
C. | (- rho overline{u_{i}^{ } u_{j}^{ }} = 2 rho overline{v} f_{v1} ( frac{ partial U_i}{ partial x_i}+ frac{ partial U_j}{ partial x_j}) ) |
D. | (- rho overline{u_{i}^{ } u_{j}^{ }} = 2 rho overline{v} f_{v1} ( frac{ partial U_i}{ partial x_j}+ frac{ partial U_j}{ partial x_i}) ) |
Answer» C. (- rho overline{u_{i}^{ } u_{j}^{ }} = 2 rho overline{v} f_{v1} ( frac{ partial U_i}{ partial x_i}+ frac{ partial U_j}{ partial x_j}) ) | |
5. |
Near the wall, the first wall damping function tends to ___________ |
A. | -1 |
B. | 1 |
C. | 0 |
D. | |
Answer» D. | |
6. |
At high Reynolds numbers, the first wall damping function becomes ___________ |
A. | -1 |
B. | 1 |
C. | 0 |
D. | |
Answer» C. 0 | |
7. |
The first wall damping function in the Spalart-Allmaras model is a function of ___________ |
A. | the product of the dynamic eddy viscosity parameter and the dynamic eddy viscosity |
B. | the ratio of the dynamic eddy viscosity parameter and the dynamic eddy viscosity |
C. | the product of the kinematic eddy viscosity parameter and the kinematic eddy viscosity |
D. | the ratio of the kinematic eddy viscosity parameter and the kinematic eddy viscosity |
Answer» E. | |
8. |
In the Spalart-Allmaras model, the dynamic eddy viscosity in terms of the kinematic eddy viscosity parameter () is given by __________ (Note: f 1 is the wall damping function and is the density of flow). |
A. | f<sub> 1</sub> |
B. | ( ) f<sub> 1</sub> |
C. | ( f<sub> 1</sub>) |
D. | ( f<sub> 1</sub>) |
Answer» B. ( ) f<sub> 1</sub> | |
9. |
The transport equation in the Spalart-Allmaras model is for the transport of ___________ |
A. | kinematic eddy viscosity parameter |
B. | kinematic eddy viscosity |
C. | dynamic eddy viscosity parameter |
D. | dynamic eddy viscosity |
Answer» B. kinematic eddy viscosity | |
10. |
The Spalart-Allmaras model differs from the RANS equations by ___________ |
A. | four extra transport equations |
B. | one extra transport equation |
C. | two extra transport equations |
D. | three extra transport equations |
Answer» C. two extra transport equations | |